1. Field of the Invention
The invention relates generally to valves and, more particularly, to a plug type control valve for controlling the flow of fluids or fluidized materials through a conduit.
2. Discussion of Prior Art
Fluid catalytic methods and structures are common in the petroleum and chemical industries. In these methods, finely divided catalyst particles are suspended in a gas and maintained in a fluid-like state. To move the catalyst particles from one vessel to another, a stream of air can be provided from a valve device. The valve device can include a hollow tube plug valve with an internal check valve to control the stream of air. The check valve can move within the plug valve between an open position, in which air flow can exit the valve device, and a closed position, in which air flow is prevented from exiting the valve device. However, air flow past the check valve can be turbulent, thus allowing catalyst particles to infiltrate the hollow tube plug valve during normal operation while lift air is flowing. These catalyst particles can cause abnormal wear within the plug valve due to catalyst erosion. Thus, it would be beneficial to modify an existing plug valve to reduce the ingress of catalyst particles into the plug valve.